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...it is smarter to go co-generation...

ja...

I would love to see a heat pump system that had high and low pressure refrigerant lines, individual throttles in each room, and tie-in ports for things like refrigerators. It always strikes me as inefficient that we stick a refrigerator up against a wall in an insulated room and then chill the room itself.

Hmm ... good argument for a more integrated heating/cooling system for the house. How about wrapping it up with electricity generation too? The Whispergen folks in New Zealand make a Stirling-cycle microCHP (Combined Heat & Power) generator suitable for the home. You could theoretically switch the flow of the cold and hot sinks with a bit of clever plumbing, and use the energy - the thermal differential, basically - otherwise wasted in generation for heating and cooling places.

Not sure how much additional instrumentation you'd need, but you could quite probably heat and cool your house with nothing more than a gas MicroCHP and a bit of well engineered plumbing & a few digital thermal sensors. You'd need to do your sums though, there's physics involved.

Disclaimer: I'm a Stirling engine fan (not that you couldn't tell).

And why do you think this is happening? Would it be that smaller generators are somehow more efficient than large, high-capacity generating plants? Or do you think that it has been impossible to get a permit to build a large high-capacity generating plant for the last 30 years or so?

I don't think per-kilowatt cost is necessarily the prime driver. The real gain is in the flexibility that comes from decentralisation of supply. A large scale generator may take 36 months to install, which is cool if you have the mandate and the organisation and the plans. But a single home or business microCHP installation can happen in one or two days, and they're sourced from an assembly line. Volkswagen AG and Whispergen (NZ) are two microCHP makers. They're both powered by natural gas, although the Whispergen is a Stirling design and more flexible in fuel source.

If you can manage growth incrementally, and serve your community needs with smaller, easier to acquire energy sources, it stands to reason that you'd be less inclined to either shortages or expensive oversupply. And in a growth scenario, it's a bit difficult to ask an existing community to pay not just for their own power capacity, but to underwrite the needs of future people too. Small is beautiful, even if it ain't cheap.

Stirling with an "i". Have a look at Whispergen in New Zealand. They sell commercial Stirling engine applications in bulk as home MicroCHP (Combined Heating and Power) generators. They might sell you just the engine, if you're truly interested.

I've been compiling an electricity industry report over the last couple of weeks. One of the interesting things I ran across was Whispergen, a company in New Zealand (I'm not affiliated with them). Quiet, low maintenance home generators based on multifuel Stirling engines. They've recently opened a new factory in Spain for high volume production.

Very interesting - if we can manufacture fluids from waste plastic that are reasonably energy-dense, the exact thermal profile of their burn may not rule out their being used to put electricity back into the grid on a wider basis. External combustion engines are quite resilient to differences in fuel type, because they really only need a thermal differential to work - not a precisely metered injection of fuel with specific burn characteristics like an internal combustion engine requires. Volkswagen and Lichtblick in Germany are also rolling out a pilot for fixed home distributed generation units, as (I believe) was reported earlier on this forum. Keyword is MicroCHP (combined heating and power).

The fact that variations in the quality of fuel can be accommodated easily argues in favour of there being an economic advantage in using them where they might otherwise not be as attractive to use. Current grid buy-back systems here in Australia are largely photovoltaic (thousands of new applications per month) in WA and QLD, but the grid does actually need to smarten up a bit to use distributed generation elsewhere. The ability to handle electricity buy-back and the ability to keep the load level is key.

Whispergen in New Zealand has been making Stirling engines with a special "wobble yoke" for many years in my city that does something similar. I should think that their much-simpler engines would be more efficient. Their website http://www.whispertech.co.nz/ and a Flash animation showing its operation http://www.whispergen.com/content/library/whispergen.html

I'm surprised no one else seems to have mentioned them.

http://www.whispergen.com/

Burn diesel, kerosene, natural gas, or propane, and generate your own electricity while providing heat and hot water. It'll get you off the grid.

Don't know how you would go about verifying these claims, but, these guys claim 800 Watts out at 1/5 gallon of gasoline per hour. If you trust the last link there, a gallon of gasoline contains 36KWh of energy, 1/5 of that is 7.2KWh, giving 11% efficiency if you're getting 800Wh of electricity out while burning 1/5 of a gallon of gas.

Kamen has a pile of Sterling related patents, many centered around more efficient conversion of fuel to mechanical output from the engine. In the past, he has been very cloak and dagger regarding his engine progress (or, at least when I visited DEKA shortly pre-Ginger release, he was). Maybe if you really care, you could approach him and see if he has working models that exceed 11% efficiency.

While that is 'interesting' that Dean wants to burn Dung, there are others who are building heilostats with Stirling engines. (That means you don't have to go gather dung for power.)

Whispergen is shipping engines, has test dishes, Solo was selling some a couple of years ago for sub-10,000 euros.

And these people were at one time claiming a $89 price point for a 1hp engine if you bought 'em in 40 foot container lots.

Dean's looking like the looser on the stirling race.

-==[NOT affiliated]==-

here's a wobble yoke flash animation.

can't find a picture of a swashplate engine but here's the old dyna-cam patent. It's not particularly clear what they're talking about but nobody seems to have online pictures. Scroll down this page about halfway and they have a cross-section drawn. If you do an image search on google under 'dyna-cam engine' you'll see what they were working on.

Get a hyperefficient Whispergen Stirling generator. It would both heat your home and provide electric power by burning natural gas. In fact, if your meter is wired correctly, at times you would be selling power back to the power companies. You can think of it as augmenting your furnace heat with a 2nd device and getting electricity (in the form of your own off-grid generator) for free.

Because the power provideres LIKE their state sponsered monopoly. It is in their interest to suffer line losses, as opposed to people putting up solar, or heating their homes with co-generation solutions GE's fuel cell solution that does NOT do co-generation, and you still can't buy or this stirling cycle engine that needs to have the cool side cooled, you could use this in a radiant heat system and a hot water tank pre-heater. (Yea, if mass produced could be in a $3k range or less, but is $16K today)

How does the power company keep its monopoly? By requiring you to take out insurance to have a grid-intertied power generation JUST to reduce your load on the grid. (In my case $180 a year. That happens to be $10 less than the electricity my 'proposed' PV would have generated in a year at $0.07 kwH) Why the insurance? Because the utility workes might get a shock....nevermind if there is no AC power on an intertie unit, the unit shuts down.

Look at oil prices, at $20 a barrel. Why? Because right now, there is a vocal group calling to get off Arab-obtained oil as a way to avoid/solve the terrorist issue. By keeping oil prices low, the demand to move from cheap energy to more expensive renewable solutions will be blunted, and the 'energy independance' voices will fade, as the masses go back to driving their big SUV's and cheap power.

Stirling engines are remarkably efficient at generating electricity. Whisper Tech has developed a system that can generate sufficient power for a home. The US-targed units run on natural gas, but they are not manufactured in sufficient quantities to be cost effective (US$12,500). We have to start somewhere, eh?
Some studies have been done using a parabolic dish or trough to drive a Stirling engine. I have investigated buying an old satellite television dish with tracking motors to track the sun. All I would have to do is paint or cover the dish with some highly reflective substance. That part is fairly cheap. I can't find the Stirling generators used in the article above. None of the Stirling engine producers seem to be selling engines to the open market.
If anyone knows where to buy a commercial solar thermal-electric Stirling system, I would like to see that posted here.